leds: gpio: Set max brightness to 1

GPIO LEDs only know 2 states: ON or OFF and do not have PWM capabilities.
However, the max brightness is reported as 255.

This patch sets the max brightness value of a GPIO controlled LED to 1.

Tested on my PinePhone 1.2.
Signed-off-by: Dylan Van Assche <me@dylanvanassche.be>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

drivers/leds/leds-gpio.c

@@ -96,7 +96,8 @@ static int create_gpio_led(const struct gpio_led *template,
 	} else {
 		state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
 	}
-	led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
+	led_dat->cdev.brightness = state;
+	led_dat->cdev.max_brightness = 1;
 	if (!template->retain_state_suspended)
 		led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 	if (template->panic_indicator)